Non-equilibrium simulations were used to evaluate diffusivities for binary mixtures of methane/CF4, propane/CF4, n-butane/CF4 and n-butane/ethane in faujasite at 300K. A formula for estimating errors in the transport coefficients was given. Non-equilibrium simulations could furnish cross-coefficients, in the Onsager matrix, with considerably lower error than in the case of equilibrium molecular dynamics. Diffusion coefficients were evaluated that could not be evaluated using equilibrium molecular dynamics. An estimation scheme based upon the Maxwell-Stefan formulation was derived for predicting multi-component diffusivities on the basis of single-component diffusion data.

Nonequilibrium Molecular Dynamics Simulations of Diffusion of Binary Mixtures Containing Short n-Alkanes in Faujasite. Chempath, S., Krishna, R., Snurr, R.Q.: Journal of Physical Chemistry B, 2004, 108[35], 13481-91